Method and apparatus for coating balloon catheters

Abstract

A coating apparatus for coating the balloon portion of a balloon catheter is described. The coating apparatus includes a rotatable member in which the catheter portion of the balloon catheter is mounted and fixed, and which causes rotation of the balloon catheter. The apparatus also includes a support member in which the distal tip of the catheter is inserted and free to rotate; and a spray nozzle directing sprayed material on the balloon surface. The inventive configuration of the coating apparatus allows the balloon catheter to be rotated along its axis with insubstantial or no wobble, which significantly improves the quality of the coating applied to the surface of the balloon.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]The present non-provisional patent application claims priority under 35 U.S.C. §119(e) from U.S. Provisional Patent Application having Ser. No. 61 / 188,929, filed on Aug. 14, 2008, and titled METHOD AND APPARATUS FOR COATING BALLOON CATHETERS, wherein the entirety of said provisional patent application is incorporated herein by reference.FIELD OF THE INVENTION[0002]The invention relates to a spray coating apparatus and methods for disposing a coating material on a medical device surface.BACKGROUND OF THE INVENTION[0003]Functional improvements to implantable or insertable medical devices can be achieved by coating the surface of the device. For example, a coating formed on the surface of the device can provide improved lubricity, improved biocompatibility, or drug delivery properties to the surface. In turn, this can improve movement of the device in the body, extend the functional life of the device, or treat a medical condition near the si...

AI Technical Summary

Benefits of technology

[0010]In one aspect, the invention provides a coating apparatus for rotatably coating an insertable or implantable medical device, such as a balloon catheter. The coating apparatus includes a rotatable member in which a catheter portion of a balloon catheter can be fixed and rotated. The rotatable member has an elongate shape with a distal end, a proximal end, and a central axis. The central axis of the rotatable member is accessible, and the catheter portion can be fixed in the rotatable member along the central axis so the catheter axis is aligned with the central axis. The coating apparatus also includes a support member having an aperture that is aligned with the central axis of the rotatable member. The support member is capable of holding the distal tip of the balloon catheter, but allows for rotation of the balloon catheter when the catheter portion is fixed and rotated by the rotatable member. The distal end of the rotatable member is separated from the support member by a gap. The gap has a length sufficient to accommodate the length of the balloon portion of the balloon catheter. The coating apparatus also includes a spray nozzle capable of delivering a spray of coating material in the gap between the distal end of the rotatable member and the support member. When a balloon catheter is mounted in position, the spray nozzle can deliver a spray of coating material to the balloon surface.

[0018]The invention provides advantages for the coating of medical devices, in particular balloon catheters. For example, the apparatus improves a balloon catheter coating process because the spraying of the entire circumference of the balloon surface can be carried out with rotational movement, and during the rotation there is little or no deviation in the distance between the balloon surface and the tip of the spray nozzle. As such, the coating apparatus and method can provide precise positioning and uniform rotation of the balloon catheter with respect to the spray head. This is achieve because the rotatable member and support member are arranged and are able to secure the balloon catheter in such a way that the axis of the balloon catheter remains straight during the rotational movement, thereby preventing unsteady or wobbly rotation of the balloon. This ultimately provides a more uniform coating because there is minimal variance of the distance between the tip of the coating nozzle and the surface of the balloon being coated while the balloon catheter is being rotated.

[0019]In addition, the apparatus is advantageous in that it can allow for rapid loading and removal of pre-inflated balloon catheters without coiling or kinking the of the catheter portions.

[0020]In addition, the apparatus is advantageous in that it can protect the catheter from extraneous coating flux.

Problems solved by technology

However, various challenges exist for the design and use of coating apparatus designed to provide coatings to medical devices.

Traditional coating methods, such as dip coating, are often undesirable as they may result in flawed coatings that could compromise the function of the device or present problems during use.

These methods can also result in coating inaccuracies, which can be manifested in variable amounts of the coated material being deposited on the surface of the device.

It has been difficult to achieve a great degree of accuracy using traditional coating methods and machines.

As another challenge, implantable or insertable medical devices are typically small and often have unusual, complex configurations.

As a general matter, the handing of these devices in an appropriate manner during a coating procedure is often challenging.

It is often difficult to fixture and manipulate the devices so they receive a desired coating of material.

It is also often difficult to prevent the coating apparatus and method from introducing defects into the formed coating.

The balloon is then inflated when the catheter reaches target site resulting in application of mechanical force sufficient to cause vessel dilation.

Applicants have found that the complex design of a balloon catheter has made the balloon portion of the catheter difficult to coat.

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